Fahrbach S E, Pfaff D W
Horm Behav. 1986 Sep;20(3):354-63. doi: 10.1016/0018-506x(86)90043-7.
Estrogen implanted directly into the medial preoptic region of pregnant Charles River Sprague-Dawley rats hysterectomized and ovariectomized on Day 16 of gestation mimics the effects of systemic estrogen treatment at this time by reducing the latency to respond to foster pups with maternal behavior (Numan, Rosenblatt, and Komisaruk, 1977). The present report describes the pup-directed responses of ovariectomized, nulliparous Zivic-Miller Sprague-Dawley rats that received bilateral medial preoptic implants of either cholesterol (n = 11) or estradiol diluted 1:10 with cholesterol (n = 11). Two days after treatment these animals were housed with three foster pups: their responsivity to pups and quality of nests built were then assessed, at first hourly and then daily. Rats receiving intracranial estradiol required significantly shorter exposures to pups than did cholesterol-treated animals before initiating carrying and grouping of 3 dispersed pups in a maternal nest during a 15-min test. On other measures, however, the groups did not differ (e.g., proportion grouping pups overnight, time required to complete retrieval of pups to the nest, time required to rebuild a disrupted nest). Animals treated with cholesterol and animals with estradiol implants did not differ in uterine weight at the time of sacrifice, suggesting that estrogen did not leak, even from this well-vascularized implant site, into the circulation. Thus, as in the pregnant animal, the facilitating effects of estrogen on maternal behavior can be mediated through the medial preoptic region; however, the effects were evident only when a test requiring retrieval of several pups within an arbitrarily short interval was given.
将雌激素直接植入在妊娠第16天进行子宫切除和卵巢切除的怀孕查尔斯河斯普拉格-道利大鼠的内侧视前区，此时可模拟全身雌激素治疗的效果，即通过减少以母性行为对寄养幼崽做出反应的潜伏期来实现（努曼、罗森布拉特和科米萨鲁克，1977年）。本报告描述了接受双侧内侧视前区植入胆固醇（n = 11）或与胆固醇按1:10稀释的雌二醇（n = 11）的去卵巢、未生育的齐维克-米勒斯普拉格-道利大鼠对幼崽的反应。治疗两天后，将这些动物与三只寄养幼崽放在一起饲养：然后评估它们对幼崽的反应性和筑巢质量，开始时每小时评估一次，然后每天评估一次。在15分钟的测试中，接受颅内雌二醇治疗的大鼠在开始将3只分散的幼崽抱到母巢中并聚集在一起之前，与接受胆固醇治疗的动物相比，需要明显更短的时间接触幼崽。然而，在其他指标上，两组没有差异（例如，过夜聚集幼崽的比例、将幼崽找回巢中所需的时间、重建被打乱的巢所需的时间）。在处死时，接受胆固醇治疗的动物和植入雌二醇的动物子宫重量没有差异，这表明即使从这个血管丰富的植入部位，雌激素也没有泄漏到循环中。因此，与怀孕动物一样，雌激素对母性行为的促进作用可以通过内侧视前区介导；然而，只有在进行一项要求在任意短的时间间隔内找回几只幼崽的测试时，这种作用才明显。
